Pests
Agrotis ipsilon Hufn. -Black Cutworm
Systematic position.
Class Insecta, order Lepidoptera, family Noctuidae, genus AgrotisSynonyms.
Scotia ipsilon Nufn., Feltia ypsilon Nufn., Agrotis ypsilon Rott.Biological group.
This species is a polyphagous pest.Morphology and biology.
Sexual dimorphism is not expressed in this species. Forewings are narrow, pointed and straight. Wing span is 40-50 mm. Pattern varies from yellowish-brown to black-brown, being sometimes darker along anterior margin. Black stria and two other black striae emerging from sub-marginal line are located outside of reniform spot. Hind wings are light-gray with dark veins and blackened external edge. Females have setaceous antennae, but males have a comb-like antennae that is 2/3 the length. Imago life span is 12 to 33 days depending on temperature, air humidity and feeding conditions of larvae. Fecundity varies in the range of 500-900 (maximum to 2000) eggs. Eggs are laid one by one, or in groups of 2-3 on leaves that touch the earth surface and they are also laid on the ground. Development of eggs lasts 3-5 (in summer) to 14 days (in autumn). Eggs are oval in form (0.5-0.6 mm in diameter and 0.4 mm in height) and have a costate surface; their color is milky-white at first, then dark-violet. Caterpillars develop over 14-35 days, reaching 40-55 mm in length during the last 6th instar. Larvae are ashy-gray with a light reddish stripe along dorsal side; skin irregularly granulated. Head and scutellum are dark-brown. Larvae pupate in soil at a shallow depth. Pupae stage lasts 13-25 days. Pupae are dark-brown in coloration. Body length is 19 to 25 mm. Over-wintering occurs during the pupal stage in northern parts of the species area and during stages of larva and moth in the south. Development of one generation proceeds 1.5-2 months into the summer. The following sources were used: Vasil'ev (1974), Pospelov (1989), Sukhareva (1999), Shchegolev et al. (1934).Distribution.
The species is widely distributed all over the world, particularly in moderate and subtropical countries of the northern and southern hemispheres, except for the far North and deserted regions of Africa and Central Asia. In Russia the Black Cutworm occurs south of the following line: St.-Petersburg - Petrozavodsk - Vologda - Perm - Tobolsk - Tomsk - Irkutsk - Blagoveshchensk, in Primorskii Territory, and also in the south of Sakhalin and in the southern Kuriles (Kunashir and Shikotan) according to the following sources: Kononenko (2003), Sukhareva (1999), Velikan et al. (1981, 1982).Ecology.
This species is a broad polyphage. It is a polycyclic species. One generation develops in the northern regions of Russia, Baltic States and Western Siberia; 2 generations develop in the central areas of the European part of Russia and in the Far East; 2-3 generations develop in the Northern Caucasus; 3-4 generations develop in Transcaucasia, Central Asia and Kazakhstan (Pospelov, 1989). The Black Cutworm is known as a migrant. It is a hygrophilic and thermophilic species and therefore it is numerous in the south, in regions with increased humidity and irrigated lands, but also in light and warm lands in the north. Optimum temperature is 26-29°C for larvae, 21-26°C for moths and pupae. Optimum relative air humidity is 65-75%. Moth flight in southern and central regions of the species area is observed at the end of April-May, lasting through all of the summer months. The species development depends on temperature and on the precipitation sum as well as conditions of larva feeding. Insect population depends on the activity of entomophages (parasites and predators) and entomopathogens. Larvae live in the top layer of the ground and emerge for feeding at night. Caterpillars of junior instars eat around leaves and senior instars gnaw around shoot stalks; the most severe damage is caused by the 1st generation larvae. In natural habitats the species prefers to develop on plants of the families Chenopodiaceae and Asteraceae. The following sources were used: Druzhelyubova (1964, 1976), Pospelov (1989), Sukhareva (1999), Shchegolev et al. (1934).Economic significance.
The Cutworm causes damage to vegetable, cucurbitaceous and industrial crops. The greatest damage it causes is to cotton, essential-oil cultures, maize, tobacco, sunflower (in Transcaucasia), tomatoes, sugar beet and potato (in the Ukraine and Byelorussia). In Southern Siberia and in the south of the Far East the pest can strongly harm vegetables, and also damage seedlings of tree species (pine, maple, Manchurian ash, and nut). Economic threshold of harmfulness is 3-5 larvae/sq. m. Control measures include: cultivation of resistant varieties, weeding, removal of crop residues from fields, deep autumn plowing, inter-row cultivation, optimum dates of early sowing, including vetch-oat sown fallows in crop rotation, digging defensive ditches and furrows, watering, application of green poisonous baits, insecticide treatments of seeds and plantlets, release of such entomophages as Trichogramma spp., and the application of bio-preparations. Monitoring is possible with the use of sex pheromone traps. The following sources were used: Dolzhenko (2004), Velikan et al. (1981, 1982), Zakharenko et al. (1985).References citations:
Dolzhenko V.I., ed. 2004. Methodical instructions on registration tests of insecticides, acaricides, molluscicides, and rodenticides in agriculture. St. Petersburg: VIZR. 363 p. (In Russian)Druzhelyubova T.S. 1964. Turnip Moth and other cutworms. In: Polyakov I.Ya., Chumakov A.E., eds. Proc. VIZR, Issue 22. Leningrad: VIZR. 80-89 p. (In Russian)
Druzhelyubova T.S. 1976. Influence of temperature and light factor on development and behavior of the Black Cutworm geographical populations, Agrotis ypsilon Rott. Entomol. obozr., 55(2): 277-285. (In Russian)
Kononenko V.S. 2003. Noctuidae. In: Ler P.A., ed. Keys to the insects of the Russian Far East. V. 5(4). Trichoptera and Lepidoptera. Vladivostok: Dal.nauka. 688 p. (In Russian)
Kopaneva L.M., ed. 1981. Keys to harmful and useful insects and mites on the industrial crops in the USSR. Leningrad: Kolos. 272 p. (In Russian)
Kopaneva L.M., ed. 1982. Keys to harmful and useful insects and mites on the vegetable plants and potato in the USSR. Leningrad: Kolos. 272 p. (In Russian)
Pospelov S.M. 1989. Noctuids - pests of agricultural crops. Moscow: Agropromizdat. 112 p. (In Russian)
Shchegolev V.N., Znamenskii A.V., Bei-Bienko G.Ya. 1934. Insect pests on field crops. Leningrad-Moscow: Sel.khozgiz. 364 p. (In Russian)
Sukhareva I.L. 1999. Noctuidae. In: Kuznetsov V.I., ed. Insects and mites - agricultural pests. V. 3, Part 2. Lepidoptera. St. Petersburg: Nauka. 332-378 p. (In Russian)
Vasil'ev V.P., ed. 1974. The pests of agricultural crops and forest plantations. V. 2. Kiev: Urozhai. 606 p. (In Russian)
Zakharenko V.A., Chenkin A.F., Cherkasov V.A., Martynenko V.I., Polyakov I.Ya. 1985. Reference book on plant protection. Moscow: Agropromizdat. 415 p. (In Russian)